electricity pulses

[C.B.]

The electricity pulses throughout the house when the shower is turned on. I have never seen this before, so any help as to what could be causing this would be much appreciated. Thanks.

 

[Lighthouse Phil]

The water is heated very quickly within the shower heating cylinder and the thermostat cuts in and out just as quick. During its heating cycle there is more of a load on the supply and the supply voltage drops slightly,, as the stat opens and stops heating, the full supply voltage is returned until the next heating cycle,,,its only a matter of seconds between the cycles. Check that the cable supplying the shower is capable of supplying the required current and is not over heating

 

[stef]

The water is heated very quickly within the shower heating cylinder and the thermostat cuts in and out just as quick. During its heating cycle there is more of a load on the supply and the supply voltage drops slightly,, as the stat opens and stops heating, the full supply voltage is returned until the next heating cycle,,,its only a matter of seconds between the cycles. Check that the cable supplying the shower is capable of supplying the required current and is not over heating

Now that sounds reasonable.

 

[Rockingit]

Any current using device will cause a drop in voltage to occur - bigger the load, larger the drop. That's why we have to size up cables correctly. In my own house, turn the 11kW shower on and the few remaining tungsten lights dim down ever so slightly. All cables correctly sized, installed and terminated, it's just V/IR at work. If I want to solve the problem, I guess I could just ask the DNO to give me a fatter cable....

OP - if the pulsing is significant, then get a competent sparky to double check all the terminations, as others have said. If that's not the issue then it might be time to talk to your energy provider as needing investigation.